Grating structure



June 23, 1942.

H. s. NAGIN 2,287,558

GRA'IING STRUCTURE Filed May 21,- 1938 2 SheetsShee l INVENTOR Ha fry S.Nag in MMrM ATTOR EYS June 23, 1942., a NAGlN I 2,287,558

' GRATING STRUCTURE Filed May 21', 1938 2 Sheets-Sheet 2 y. 25 e fglfi.5

- INVENTOR Harry SJV'qgzln WWW rm A TTORNEYS Patented June 23, 1942GRATING STRUCTURE Harry S. Nagin, Pittsburgh, Pa., assignor to RelianceSteel Products Company, Rankin, Pa., a corporation of PennsylvaniaApplication May 21, 1938, Serial No. 209,255

4 Claims.

This invention relates to grating structures and is particularlyapplicable to grating structures such as are used for reinforcing inbridge floors, runways, vault covers, loading platforms, stair-treadsand in other locations. The grating structure may be used with orwithout a filling of concrete or other material.

It is the common practice at present to .form bridge floors and the likeby laying previously assembled units or slabs over a skeleton supportingstructure, such as the sills or stringers of a bridge. Such units orslabs of a convenient size are fabricated in the shop from metalelements and after assembly in position in the structure, the units orslabs are usually welded together to form a continuous floor. Each unitin general is made of spaced apart bearer bars of a desired size andshape secured together by transverse cross bars usually at the top. Inmany structures bottom cross bars are also used. The tops of the crossbars and the top bearer bars are usually in the same plane and serve assurface armoring when a filling material is employed. After assembly,the spaces between the various bars of the slab are commonly filled withconcrete or other material, although in some instances the structure isused without a filling as an open mesh fioor.

It is a fairly wide spread practice in the art to secure the bearer barsand cross bars together by electric pressure welding. In some instancesit is preferred to join the bearer bars and cross bars by passing thecross bars through slots in the webs of the bearer bars and then todeform or fasten the bars together so as to make a rigid structure.According to my invention the joining of the bearer bars is accomplishedby a comparatively simple arrangement of cross bars and slots in thewebs of the bearer bars to form a rigid structure.

Such structures are usually subject to severe strain and it is essentialthat the various shearing, bending, and transverse stressses be properlydistributed. It is one of the objects of my invention to provide a unitor slab which is simple and inexpensive to fabricate and erect and whichwill adequately resist the various stresses to which it is subjected.

By use of a structure made according to my invention, the variousstresses encountered, are

effectively taken care of and the structure is simple and inexpensive tofabricate and erect, and the completed structure is a rigid and strongone.

In the accompanying drawings where I have shown, for purposes orillustration only, certain preferred embodiments of my invention:

Figure 1 is a fragmentary plan of a unit or slab;

Figure 2 is an elevation along the line II-II of Figure 1;

Figure 3 is a fragmentary detail of a suitable top cross bar;

Figure 4 is a fragmentary view in enlarged perspective showing a portionof a bearer bar with a vertical slot;

Figure 5 is a fragmentary view in enlarged perspective of a portion of abearer bar with an inclined slot;

Figure 6 is a fragmentary view in elevation, showing the cross bar ofthe construction shown in Figure 5, in final position;

Figures 7 and 8 are fragmentary details in elevation showing 'ahorizontal slot, and with a cross bar in position; v

Figure 9 is a fragmentary view in perspective of a top cross barsuitable for use in connection with the form of slot shown in Figures 7and 8, but to a smaller scale;

Figures 10 and 11 are fragmentary views in elevation of still anotherform of slot with a cross bar in various positions;

Figure 12 is a fragmentary cross section along the line XII-XII ofFigure 11;

Figure 13 is a fragmentary View of a top cross bar suitable for use inconnection with the form of slot shown in Figures 10 and 11;

Figure 14 is'a fragmentary View in elevation of another slot and crossbar construction;

Figure 15 is a View along the line XV-XV of Figure 14;

Figure 15a. is a fragmentary view in perspective of a top cross barsuitable for use in the construction shown in Figures 14 and 15;

Figure 16 is a fragmentary view in elevation showing still anotherconstruction;

Figures 1'7 and 18 are views along the line XVIIXVII of Figure 16,Figure 17 showing the construction whennearly finished, and Figure 18showing the completed construction;

Figure 19 is a fragmentary View in perspective of a top cross barsuitable for use in the construction shown in Figures 16, 17 and 18;

Figure 20 is a fragmentary view in perspective of a top cross barsuitable for use in the construction shown in Figures 21 and 22;

Figure 21 is a fragmentary view in elevation showing still another formof construction;

'Figure 22 is a view along the line XXII-XXII of Figure 2.1-;

Figure 23 is a view along the line XXIII XXIII of Figure 24;

Figure 24 is a fragmentary view in elevation showing still another formof construction; and

Figure 25 is a fragmentary view in perspective of a top cross barsuitable for use in the construction shown in Figures 23 and 24.

In the drawings there is shown in Figures 1 and 2 a portion of a slab orunit which consists of spaced apart longitudinally extending main barsor bearer bars 2 of a. desired shape and size. The bearer bars 2 hereindescribed and illustrated have a web 3, a head 4 and a base 5. Thelongitudinal bars 2 are connected adjacent their tops by cross bars 6and the bases are usually connected by cross bars 7 near the bottom ofthe webs. In some instances, the bottom cross bars 7 may be dispensedwith. The top of the bearer bars 2 and the top of the cross bars 6 liein substantially the same plane when assembled in the or other fillingmaterial, but it is to be understood that in some installations unfilledunits maybe used.

The web 3 of the longitudinal bearer bar 2 is slotted near the head 4.The slots may assume various forms, but all of them are so arranged asto have a locking lug associated therewith to lock the transverse topcross bars 6 in position.

In the construction shown in Figures 1 through 4 there is shown a unitin which the web slots 9 are vertical. The slots 9 are of a size toreceive top cross bars 6 (Figure 3). Cooperating with the lower portionof the slot is a lug I0 stamped out of the material of the web. Thetransverse bars 6 are substantially rectangular in cross-section and oneedge thereof has a plurality of recesses II with sloping bottom portionsI2. The recesses i I are shaped to conform to the shape and size of thehead 4 of the bearer bars 2 and are spaced apart the same distance asthe spacing of the bearer bars 2. The depth of the slots 9 issubstantially the same as the depth of the bars 6, and the lug I0 is sopositioned that when the cross bars 6 are raised into the final positionshown in Figure 2, the top portion of the lug it, when forced back intothe slot 9, as shown in dotted lines in Figure 4, and numbered I 0,contacts the bottom of the bar 6 and holds it securely in position withthe bottom of recesses ll tightly pressed against the bottom of head 4and the top of the bar 6 is in substantially the same plane as the topof the head 4.

In assembling this unit, the longitudinal bars 2 are properly spaced andthe top cross bars 6 are passed through the aligned slots 9 until therecesses l I, which are spaced apart the same distance as the space ofthe girder members 2, are in position to cooperate with the heads 4 ofthe bars 2. The top bars 6' are then raised into the position shown inFigure 2 where the tops of the cross bars and the tops of the girderbars 2 are in substantially the same plane. The lugs ID are then forcedback into the slots 9 to lock the cross bars 6 securely in position.

The bottom parts of the bearer bars 2 may be secured together by bottomtransverse bars I against the tops of the slots 9a.

which may conveniently be of circular cross-section. These bars arepassed through appropriate holes in the lower part of webs 3 adjacentthe base 5. The bars 1 are then welded to the webs 3. If desired, thebottom cross bars "i may be of any other section, for example,rectangular. If rectangular bars are used, they may be passed throughhorizontal slots in the webs 3 and after the bars 1 are in position,these portions of the bars between the adjacent bearer bars 2 aretwisted through an angle of about thus looking the bottom cross bars andthe longitudinal bars in fixed relation.

In Figure 5 there is shown one of the preferred constructions, in whichthe slots 9a are at an angle to the vertical. I have found an angle ofabout 30 to be a convenient one. Each of the slots So has associatedwith it a lug lfla formed from the material of the web 3a. The lengthand thickness of the slots is sufficient to accommodate the top crossbars 6. In this inclined slot construction, the top cross bars 6 arepassed through the aligned slots 9a and the bars 6 are then movedupwardly along the slots until the bottoms Id of the recesses II arepressed firmly The position of the slots Se is such that when the lugs[0a are forced back into the slots 9a, the tops of the lugs contact thebottoms of the bars 6. After the bars 6 are in their uppermost positionin the slots, the portions [3 between the recesses II are turnedupwardly to a vertical position I 3a, as shown in Figure 6. The slots 9aand the bars 6 are so proportioned that when the bottoms i 4 of recessesII contact the bottoms of the heads ta, the top edges of portions I3 ofthe bars 6, when bent upwardly to the Vertical position, will be insubstantially the same plane as the tops.

of the heads 4a.

In the slot construction shown in Figures '7 and 8, the slots 9b aresubstantially horizontal and have associated with them outstanding lugslob formed from the material of the webs 3b. The cross bars I5 (Figure9), used in this construction, are substantially rectangular incrosssection and one edge thereof has a plurality of recesses I6, withbottoms lBw, formed at intervals corresponding to the spacing of thebearer bars of the slab. In assembling this construction, the bars I5are passed through the aligned slots 92) in the spaced apart bearerbars. The portions l1 between the recesses I6 are then bent upwardly toa vertical position, asshown in Figures 7 and 8, and the lugs 1b arebent back into the slots 9b where they contact the corner of the bendformed in the bars i5. The size of the slots, their position in the websand the bars 15 are all so proportioned that the bars [5 are securelyheld in slots 9b and the top edges of the portions I! are insubstantially the same plane as the tops of the heads 41). This isclearly cross bars 6c areof angular shape and have recesses He formed inone leg of the angle at spaced apart intervals corresponding to thedesired spacing apart of the bearer bars. In assembling this unit,.thecross bars 60 are inserted aasmss in the slots 90 as shown in Figure 10.The bars 60 are then moved upwardly and to the right to the positionshown in Figure 11, in which position the top parts of the bar 6c are insubstantially the same plane as the tops of the heads 40. The lugs I arethen forced back into the slots 90 where they bear against the bottomsof the bars 60 and hold them securely in position. The size of theslots, their location in the webs and the proportions of the bars 60 areall such that when the bars 60 are in the position shown in Figure 11,the bottoms of recesses H'c bear tightly against the bottoms of theheads 40, the tops of the bars 60 are in substantially the same plane asthe tops of the heads 40 and the lugs lflc bear against the bottoms ofthe bars 60.

In Figures 14 and there is illustrated a construction in which the webs3d have horizontal slots 9d formed therein near the bottom of the headportions 4d of the bearer bars. Through these slots the cross bars 19,which are substantially the same size as. the slots, are passed. Thecross bars I9 have recesses formed at intervals along one edge of thecross bar. The recesses 20 are formed so that there is a tab portion 21in the recess, the width of the cross bars at the tab portions beinguninterrupted. The recesses 20 are spaced, apart a distancecorresponding to the desired spacing apart of the bearer bars. Inassembling this construction the cross bars l9 are threaded through thealigned slots 9d until the tab portions 2| are in register with the webs3d of the bearer bars. The portions 22 between the recesses 20 of thecross bars 19 are then bent through an angle of approximately 90 so thatthe slotted edges of the cross bars I9 are in substantially the sameplane as the top of the bearer bar heads 4d as shown in Figure 14. Theposition of the slots 9d and the depth of. the recesses 20 are such thatthe. top of the cross bars, I9 and the top of the heads 4d lie insubstantially the same plane when the unit, is assembled. Theuninterrupted Width of the cross bars 19 at the tab portions insuresthat the slots 901- will be completely filled, preventing movement ofthe. I

cross bars along the bearer bars.

In Figures 16, 17 and 18 I have shown a construction in which the bearerbars have a narrow welding rib 23 projecting vertically upward from thecenter of the top of the heads 46. Through the web 3e generallyhorizontal slots 9e are formed. Each slot has an adjoining cut outportion 24 extending downwardly at right angles to the longitudinal axisof the slot. The cross bars 25 used in this construction have recesses26 formed in one side thereof, the recesses having a projecting tabportion 21 and lug portions 28 as shown in Figure 19. The recesses 26are spaced apart the same distance as the desired spacing of the crossbars with which they are used. In assembling this construction, the bars25 are passed through the slots Be, the lugs 28 passing through theportions 24 of the slots. The center of the tab portions are placed inline with the center line of the webs 3c of the cross bars. The portions29 of the cross bars 25 between the recesses 26 are then bent upwardlyto the position shown in Figure 17 and the lugs 28 are forced into theposition shown in Figure 18 where the ends thereof are in close contactwith the sides of the welding ribs 23. The proportions of the variousparts of the bearer bars and the cross bars are such that the top edgesof the portions 29 of the bearer bars 25 and the top of the welding ribs23 lie in substantially the same plane.

In Figures 21 and 22 there is illustrated a construction in which bearerbars similar to those shown in connection with Figures 16, 17 and 18 areused. In this construction the slots 9 f in the webs 3f are vertical andhave associated with them lugs lflf formed from the material of the webs3]. At the top of the slot there is an adjoining out out portion 30projecting generally at right angles to the slot as shown in Figure 21.The top of the slot is preferably situated immediately adjacent thebottom of the heads 4 and extends downwardly a sumcient distance toaccommodate the cross bar 3|. The cross bars 3| (see Figure 20) aresubstantially rectangular in cross section and one edge thereof has aplurality of recesses 32 formed at intervals corresponding to thedesired spacing of the bearer bars. At the sides of the recesses 32,adjacent the top there is provided projecting lugs 33. In assemblingthis construction, the cross bars 32 are passed through the alignedslots 9f in the spaced apart bearer bars. The bars 31 are then movedupwardly to the position shown in Figure 21 and the lugs lllf are forcedback into the slots 9 and the lugs 33 are deformed so as to contact thesides of the welding ribs 34 projecting upwardly from the heads 4]. Thebars 3| are so formed and the slot 3 so shaped and positioned that whenthe cross bars 3! are in the position shown in Figures 21 and 22, thesides of the recesses 32 closely engage the sides of the heads 4 of thebearer bars. The lugs 33 are in close contact with the welding ribs 34and the top of the bearer bars 3| are in substantially the same plane asthe top of the welding ribs 34.

In the construction shown in Figures 23 and 24, there are providedbearer bars of inverted T shape having a web portion 35 and a baseportion 36. A horizontal slot 31 is formed a short distance below thetop of the web 35. This slot is the proper size to accommodate the crossbar 38 shown in Figure 25. The cross bar 38 has recesses 39 formed inone edge thereof at spaced apart intervals corresponding to the spacingof the bearer bars with which it is used. The recesses 39 have tabportions 43 therein, the width of the bar at the tab portions beinguninterrupted. In assembling this construction, the bars 38 are passedthrough the aligned slots 31 until the centers of the tab portions 40are in line with the center line of the webs 35. The portions 4| betweenthe recesses 39 of the cross bars 38 are then rotated through an angleof approximately The portions of the cross bar between the bearer bars Mwill then be vertical. The location of the slot 31 and the depth of therecesses 39 are such that the tops of portions 41 of the cross bars 38and the tops of the webs 35 of the bearer bars are in substantially thesame plane in the completed unit as shown in Figure 24.

It is understood in all of the constructions illustrated that the topcross bars may be welded to the heads as shown, for example, in Figure12, but this welding is not necessary to a rigid and strong structure.It is also understood that the recesses in the cross bars may closelyfollow the conformation of the heads of the bearer bars, as shown inFigure 3, or may generally follow them as shown in Figure 9.

In some instances it will be desirable to provide plates I8 between thebase portion of the bearer bars to serve as bottom form plates for theconcrete fill, if used. These plates 18 may rest on the base portionsand, if desired, may be spot welded thereto at intervals,

While I have shown and described several specific preferred embodimentsof my invention, it will beunderstood that I do not wish to be limitedprecisely thereto and that various modifications may be made within thescope of the following claims.

I claim:

1. In a grating structure a plurality of bearer bars set on edge inspaced parallel relation, said bars having a bulbous uninterrupted headportion and a web portion, aligned straight slots in the web portionadjacent the head portion and fiat cross bars disposed to extend throughthe slots of adjoining bearer bars, the top portion of said cross barshaving recesses to conform to the head portion, and a tab portionextending from the base of each recess, the bottoms of said cross barsbeing continuous, the cross bar having bendable portions between therecesses which project vertically upwardly in thestructure, the slotsbeing so disposed and the bars so proportioned that the cross bars inthe structure extend substantially to the top of the bearer bars and thetab portions lie in the slots, the top portions of the cross barsbetween the bearer bars being substantially straight.

2. In a grating structure a plurality of bearer bars set on edge inspaced parallel relation, said bearer bars including a bulbous headhaving a rib projecting vertically upwardly from the center thereof anda web portion below the head, aligned rectangular slots in the Webportion ad" jacent the bottom of the head, a cut out portion extendingdownwardly at right angles to the lon gitudinal axis of the slot, andrectangular cross bars extending through the aligned slots, one edge ofthe cross bars having recesses, the sides of which lie along the sidesof the bulbous head, a tab portion projecting from the cross bar at thebottom of each recess and received in the horizontal slots of the bearerbars, and lug por tions which extend into the recesses to a pointadjacent the rib of the head, the bottoms of said cross bars beingcontinuous, the cross bars having portions between the recesses which extend vertically and substantially straight horizontally between thebearer bars, the slots being so disposed and the bars. so proportionedthat the'p'ortio'ns of the cross bars between the bearer bars extendsubstantially to the top of the ribs of the bearer bars, the tabportions lie in the slots and the leg portions extend across the edge ofthe bulbous head to the rib thereof.

3. In a grating structure, a plurality of bearer bars set on edge inspaced parallel relation, said bars having a web portion and a topportion, the top portion of the bars being continuous, straight alignedslots in the web portion adjacent to the top portion and flat cross barsdisposed to extend through the slots of adjoining bearer bars, the topsof said cross bars having recesses to conform to the top portion of thebearer bars, and a tab portion extending from the cross bars at the baseof each recess, the bottoms of said cross bars being continuous and theparts of the cross barsextending between the said bearer bars being bentupwardly to a position Whichis vertical when the structure ishorizontal, the top portions of the cross bars extending between thebearer bars being straight.

4. In a grating structure, a plurality of bearer bars set on edge inspaced parallel relation, said bars having a web portion and a topportion, the top portion'of the bars being continuous, straight alignedslots in the web portion adjacent to the top portion and flat cross barsdisposed to extend through'the slots of adjoining bearer bars, the topsof said cross bars having recesses to com form to the top portion of thebearer bars, and spaced apart the same distance as the bearer bars, andatab portion extending from the cross bars at the base of each recesswhich registers in the slots, the width of the cross bar at the tabportion being the same as the width of the rest of the cross bar andsubstantially equal to the width of the slotsin the web portion, saidcross bars having portions extending between the recesses which are bentinto a vertical plane when said grating structure is horizontal, the

top portions of the cross bars being substantially straight, the bottomof each cross bar being con-- tinuous.

HARRY S. NAGIN.

